1. Technical Field
The present invention relates to a headlamp for a vehicle, and more particularly to a headlamp for a vehicle which does not dazzle the driver of a vehicle coming in the opposite direction.
2. Related Art
In general, a vehicle includes a lighting device having an illumination function of allowing the driver of the vehicle to see objects in the front of the vehicle at night traveling and a notification function of notifying drivers of other vehicles or pedestrians of a traveling state of the vehicle. For example, a headlamp or a fog lamp is used for illumination, while an indicator lamp, a rear lamp, a brake lamp or a side marker is used for notification.
FIG. 1 is a view schematically illustrating a conventional projection type headlamp for a vehicle. As the projection type headlamp possesses a characteristic of focusing light on one point, it is advantageous over a clear type headlamp in terms of light distribution. Also, the projection type headlamp imparts a sporty appearance.
The light emitted from a light source 11 is reflected from a mirror surface 12 of a certain shape, for example, an oval, and then is focused on one point 16 in the front of the light source 11. The focused light is refracted by a refraction lens 15 provided in the front of the lamp, and then is radiated in a forward direction. Upwardly emitted light among the emitted light is reflected from the mirror surface 12 to progress in a downward direction, and downwardly emitted light is reflected from a mirror surface 13 to proceed in an upward direction.
The projection type headlamp 10, unlike the clear type headlamp, focuses the light reflected from the mirror surface 12 on one point 16. Consequently, the projection type headlamp 10 can form various light distribution patterns by slightly changing the shape of a shield 14 around the point 16.
A recent technology proposed an adaptive front lighting system that can change light distribution patterns according to driving conditions of a vehicle, for example, traveling speed, road surface and surrounding brightness.
The adaptive front lighting system includes a plurality of light shade parts for interrupting a portion of the light emitted from a light source to determine a light distribution pattern, thereby adaptively changing the light distribution pattern in accordance with driving conditions. That is, the light shade parts are disposed along a circumference of a cylindrical body, the respective light shade parts have respective light distribution patterns, and the cylindrical body is rotated to change the light distribution pattern.
The adaptive front lighting system, however, has a drawback. Specifically, no light shading may occur between the light shade parts during the rotation of the body, that is, the light shade part may be opened. As a result, the driver of a vehicle coming in the opposite direction can be dazzled, which may cause a traffic accident.
Japanese Utility Model Registration No. 2577071 discloses a technique to solve the-above described problem associated with the opening of light shade part, in which the whole structure with the light shade parts is moved up or down by a cam when the light distribution pattern is changed. However, this technique entails frequent vertical movement, which may deteriorate the durability, and requires additional components, which may increase manufacturing costs.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.